<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.10/dist/vue.min.js"></script>
</head>

<body>
    <div id="app">

        <div>
            <input type="text" v-model="value">
            <button @click="add">添加</button>
        </div>
        <div>
            <ul>
                <li v-for="l in list">{{l}}</li>
            </ul>
        </div>
    </div>
    <script>
        new Vue({
            el: "#app",
            data: {
                value: '',
                list: []
            },
            methods: {
                add() {
                    this.list.push(this.value),
                        this.value = ""
                }
            }
        })
    </script>
</body>

</html>